Slash Film points to a recent tweet from Rachel Nichols, who played Scarlett in the first film. According to the actress, only three of the players in that movie are returning. See for yourself:

So that would be Channing Tatum as Duke, Ray Park as Snake Eyes and Lee Byung-hun as Storm Shadow. As Slash points out, surely this decision is in part a money one -- the first film didn't make a bundle, and so the sequel will be looking to keep costs as low as possible.